Evaluation of Normalization Strategies Used in Real-time Quantitative PCR Experiments in HepaRG Cell Line Studies

Abstract BACKGROUND The HepaRG cell line is widely used as an alternative for primary human hepatocytes for numerous applications, including drug screening, and is progressively gaining importance as a human-relevant cell source. Consequently, increasing numbers of experiments are being performed with this cell line, including real-time quantitative PCR (RT-qPCR) experiments for gene expression studies. CONTENT When RT-qPCR experiments are performed, results are reliable only when attention is paid to several critical aspects, including a proper normalization strategy. Therefore, in 2011 we determined the most optimal reference genes for gene expression studies in the HepaRG cell system, according to the MIQE (Minimum Information for Publication of Quantitative Real-Time PCR Experiments) guidelines. This study additionally provided clear evidence that the use of a single reference gene [glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ribosomal protein S18 (RPS18), or actin, beta (ACTB)] was insufficient for normalization in HepaRG cells. Our screening of relevant studies published after our study suggested that the findings of our study were completely ignored. SUMMARY In none of the 24 reviewed studies was a proper normalization method used. Only 1 reference gene was included for normalization in 21 out of the 24 reported studies we screened, with RPS18 and GAPDH used most frequently, followed by hypoxanthine phosphoribosyltransferase 1 (HPRT1), glutathione synthetase (GSS) (hGus), β-2 microglobin (B2M), and acidic ribosomal phosphoprotein P0 (36B4). For 2 studies the use of multiple reference genes (2 and 3) was reported, but these had not been prevalidated for expression stability in HepaRG cells. In 1 study, there was no evidence that any reference gene had been used. Current RT-qPCR gene expression studies in HepaRG cells are being performed without adequate consideration or evaluation of reference genes. Such studies can yield erroneous and biologically irrelevant results.

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Selection and validation of reference genes for quantitative gene expression analyses in persimmon (Diospyros kaki Thunb.) using real-time quantitative PCR

Biologia Futura ◽

10.1556/019.70.2019.24 ◽

2019 ◽

Vol 70 (4) ◽

pp. 261-267

Author(s):

Gaigai Du ◽

Liyuan Wang ◽

Huawei Li ◽

Peng Sun ◽

Jianmin Fu ◽

...

Keyword(s):

Gene Expression ◽

Real Time ◽

Reference Gene ◽

Reference Genes ◽

Developmental Stages ◽

Suitable Reference Gene ◽

Diospyros Kaki ◽

Stable Gene ◽

Expression Studies ◽

Gene Expression Studies

Background and aims Persimmon (Diospyros kaki) is an economically important fruit tree species with complex flowering characteristics. To obtain accurate expression pattern analysis results, it is vital to select a reliable gene for the normalization of real-time quantitative polymerase chain reaction data. The aim of this study was to identify the optimal internal control gene among six candidate genes for gene expression analysis in different persimmon organs and developmental stages. Materials and methods This analysis was conducted using geNorm and NormFinder software to show differences in the stability of the six reference genes among tissues and floral developmental stages of the same plant. Results Although genes that exhibited moderate expression in NormFinder revealed slightly different expression stabilities than those obtained by geNorm, both sets of results showed that GAPDH was the best reference gene in different organs and floral buds at different developmental stages, whereas 18SrRNA was the least stable gene. Conclusions Based on the overall ranking, GAPDH is the most suitable reference gene and is highly recommended for gene expression studies in different organs and different developmental stages of persimmon. This study provides useful reference data for future gene expression studies and will contribute to improving the accuracy of gene expression results in persimmon.

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Reference genes for mesangial cell and podocyte qPCR gene expression studies under high-glucose and renin-angiotensin-system blocker conditions

PLoS ONE ◽

10.1371/journal.pone.0246227 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0246227

Author(s):

Nicole Dittrich Hosni ◽

Ana Carolina Anauate ◽

Mirian Aparecida Boim

Keyword(s):

Gene Expression ◽

Real Time ◽

Reference Gene ◽

High Glucose ◽

Real Time Pcr ◽

Reference Genes ◽

Mesangial Cell ◽

Mesangial Cells ◽

Expression Studies ◽

Gene Expression Studies

Background Real-time PCR remains currently the gold standard method for gene expression studies. Identification of the best reference gene is a key point in performing high-quality qPCR, providing strong support for results, and performing as a source of bias when inappropriately chosen. Mesangial cells and podocytes, as essential cell lines to study diabetic kidney disease (DKD) physiopathology, demand accurate analysis of the reference genes used thus far to enhance the validity of gene expression studies, especially regarding high glucose (HG) and DKD treatments, with angiotensin II receptor blockers (e.g., losartan) being the most commonly used. This study aimed to evaluate the suitability and define the most stable reference gene for mesangial cell and podocyte studies of an in vitro DKD model of disease and its treatment. Methods Five software packages (RefFinder, NormFinder, GeNorm, Bestkeeper, and DataAssist) and the comparative ΔCt method were selected to analyze six different candidate genes: HPRT, ACTB, PGAM-1, GAPDH, PPIA, and B2M. RNA was extracted, and cDNA was synthesized from immortalized mouse mesangial cells and podocytes cultured in 4 groups: control (n = 5; 5 mM glucose), mannitol (n = 5; 30 mM, as osmotic control), HG (n = 5; 30 mM glucose), and HG + losartan (n = 5; 30 mM glucose and 10−4 mM losartan). Real-time PCR was performed according to MIQE guidelines. Results We identified that the use of 2 genes was the best combination for qPCR normalization for both mesangial cells and podocytes. For mesangial cells, the combination of HPRT and ACTB presented higher stability values. For podocytes, HPRT and GAPDH showed the best results. Conclusion This analysis provides support for the use of HPRT and ACTB as reference genes in mouse mesangial cell studies of gene expression via real-time PCR, while for podocytes, HPRT and GAPDH should be chosen.

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Evaluation of reference genes for gene expression studies in pig muscle tissue by real-time PCR

Czech Journal of Animal Science ◽

10.17221/1428-cjas ◽

2011 ◽

Vol 56 (No. 5) ◽

pp. 213-216 ◽

Cited By ~ 2

Author(s):

M. Nesvadbová ◽

A. Knoll

Keyword(s):

Gene Expression ◽

Real Time ◽

Reference Gene ◽

Muscle Tissue ◽

Reference Genes ◽

Expression Profiles ◽

Quantitative Polymerase Chain Reaction ◽

Expression Studies ◽

Gene Expression Studies ◽

The Stability

The selection of reference genes is essential for gene expression studies when using a real-time quantitative polymerase chain reaction (PCR). Reference gene selection should be performed for each experiment because the gene expression level may be changed in different experimental conditions. In this study, the stability of mRNA expression was determined for seven genes: HPRT1, RPS18, NACA, TBP, TAF4B, RPL32 and OAZ1. The stability of these reference genes was investigated in the skeletal muscle tissue of pig foetuses, piglets and adult pigs using real-time quantitative PCR and SYBR green chemistry. The expression of stability of the used reference genes was calculated using the geNorm application. Different gene expression profiles among the age categories of pigs were found out. RPS18 has been identified as the gene with the most stable expression in the muscle tissue of all pig age categories. HPRT1 and RPL32 were found to have the highest stability in piglets and adult pigs, and in foetuses and adults pigs, respectively. The newly used reference gene, TAF4B, reached the highest expression stability in piglets.

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Reference genes for mesangial cell and podocyte qPCR gene expression studies under high-glucose and renin-angiotensin-system blocker conditions

10.1101/2021.01.19.427251 ◽

2021 ◽

Author(s):

Nicole Dittrich Hosni ◽

Ana Carolina Anauate ◽

Mirian Aparecida Boim

Keyword(s):

Gene Expression ◽

Real Time ◽

Reference Gene ◽

High Glucose ◽

Real Time Pcr ◽

Reference Genes ◽

Mesangial Cell ◽

Mesangial Cells ◽

Expression Studies ◽

Gene Expression Studies

ABSTRACTBackgroundReal-time PCR remains currently the gold standard method for gene expression studies. Identification of the best reference gene is a key point in performing high quality qPCR, providing strong support for results, as well as performing as a source of bias when inappropriately chosen. Mesangial cells and podocytes, as essential cell lines to study diabetic kidney disease (DKD) physiopathology, demand accurate analysis of the reference genes used so far to enhance validity of gene expression studies, especially regarding high glucose (HG) and DKD treatments, with angiotensin II receptor blockers (e.g. Losartan) being the most commonly used. This study aimed to evaluate the suitability and define the most stable reference gene for mesangial cells and podocytes studies of an in vitro DKD model of disease and its treatment.MethodsFive software packages (RefFinder, NormFinder, GeNorm, Bestkeeper, and DataAssist) and the comparative ΔCt method were selected to analyze six different candidate genes: HPRT, ACTB, PGAM-1, GAPDH, PPIA, and B2M. RNA was extracted and cDNA was synthesized from immortalized mouse mesangial cells and podocytes cultured in 4 groups: control (n=5; 5mM glucose), mannitol (n=5; 30mM, as osmotic control), HG (n=5; 30mM glucose), and HG + losartan (n=5; 30mM glucose and 10-4 mM of losartan). Real-time PCR was performed according to MIQE guidelines.ResultsWe identified that the use of 2 genes is the best combination for qPCR normalization for both mesangial cell and podocytes. For mesangial cells, the combination of HPRT and ACTB presented higher stability values. For podocytes, HPRT and GAPDH showed the best results.ConclusionThis analysis provides support for the use of HPRT and ACTB as reference genes in mouse mesangial cell studies of gene expression via real-time PCR technique, while for podocytes, HPRT and GAPDH should be chosen.

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Validation of Reference Genes for Gene Expression Studies in Virus-Infected Nicotiana benthamiana Using Quantitative Real-Time PCR

PLoS ONE ◽

10.1371/journal.pone.0046451 ◽

2012 ◽

Vol 7 (9) ◽

pp. e46451 ◽

Cited By ~ 176

Author(s):

Deshui Liu ◽

Lindan Shi ◽

Chenggui Han ◽

Jialin Yu ◽

Dawei Li ◽

...

Keyword(s):

Gene Expression ◽

Real Time ◽

Real Time Pcr ◽

Nicotiana Benthamiana ◽

Reference Genes ◽

Quantitative Real Time Pcr ◽

Expression Studies ◽

Gene Expression Studies

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Selection and Validation of Appropriate Reference Genes for Gene Expression Studies in Schima Superba

10.21203/rs.3.rs-145449/v1 ◽

2021 ◽

Author(s):

Zhongyi Yang ◽

Rui Zhang ◽

Zhichun Zhou

Keyword(s):

Gene Expression ◽

Reference Gene ◽

Reference Genes ◽

Geometric Mean ◽

Gene Transcript ◽

Expression Stability ◽

Schima Superba ◽

Expression Studies ◽

Gene Expression Studies ◽

Different Tissues

Abstract Background Quantitative real-time PCR (qRT-PCR) is a reliable and high-throughput technique for gene expression studies, but its accuracy depends on the expression stability of reference genes. Schima superba is a strong resistance and fast-growing timber specie. However, so far, reliable reference gene identifications have not been reported in S. superba. In this study, we screened and verified the stably expressed reference genes in different tissues of S. superba.Results Nineteen candidate reference genes were selected and evaluated for their expression stability in different tissues. Three software programs (geNorm, NormFinder, and BestKeeper) were used to evaluate the reference gene transcript stabilities, and comprehensive stability ranking was generated by the geometric mean method. Our results identified that SsuACT was the most stable reference gene, SsuACT + SsuRIB was the best reference genes combination for different tissues. Finally, the stable and less stable reference genes were verified using the SsuSND1 expression in different tissues.Conclusions This is the first report to verify the appropriate reference genes for normalizing gene expression in S. superba for different tissues, which will facilitate future elucidation of gene regulations in this species, and useful references for relative species.

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Selection and validation of reference genes for gene expression studies in Klebsiella pneumoniae using Reverse Transcription Quantitative real-time PCR

Scientific Reports ◽

10.1038/s41598-018-27420-2 ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 16

Author(s):

Ana Érika Inácio Gomes ◽

Leonardo Prado Stuchi ◽

Nathália Maria Gonçalves Siqueira ◽

João Batista Henrique ◽

Renato Vicentini ◽

...

Keyword(s):

Gene Expression ◽

Klebsiella Pneumoniae ◽

Real Time ◽

Reverse Transcription ◽

Real Time Pcr ◽

Reference Genes ◽

Quantitative Real Time Pcr ◽

Expression Studies ◽

Gene Expression Studies

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Selecting and validating reference genes for quantitative real-time PCR in Plutella xylostella (L.)

Genome ◽

10.1139/gen-2017-0176 ◽

2018 ◽

Vol 61 (5) ◽

pp. 349-358 ◽

Cited By ~ 6

Author(s):

Yanchun You ◽

Miao Xie ◽

Liette Vasseur ◽

Minsheng You

Keyword(s):

Gene Expression ◽

Real Time ◽

Plutella Xylostella ◽

Real Time Pcr ◽

Reference Genes ◽

Developmental Stages ◽

Quantitative Real Time Pcr ◽

Experimental Conditions ◽

Expression Studies ◽

Gene Expression Studies

Gene expression analysis provides important clues regarding gene functions, and quantitative real-time PCR (qRT-PCR) is a widely used method in gene expression studies. Reference genes are essential for normalizing and accurately assessing gene expression. In the present study, 16 candidate reference genes (ACTB, CyPA, EF1-α, GAPDH, HSP90, NDPk, RPL13a, RPL18, RPL19, RPL32, RPL4, RPL8, RPS13, RPS4, α-TUB, and β-TUB) from Plutella xylostella were selected to evaluate gene expression stability across different experimental conditions using five statistical algorithms (geNorm, NormFinder, Delta Ct, BestKeeper, and RefFinder). The results suggest that different reference genes or combinations of reference genes are suitable for normalization in gene expression studies of P. xylostella according to the different developmental stages, strains, tissues, and insecticide treatments. Based on the given experimental sets, the most stable reference genes were RPS4 across different developmental stages, RPL8 across different strains and tissues, and EF1-α across different insecticide treatments. A comprehensive and systematic assessment of potential reference genes for gene expression normalization is essential for post-genomic functional research in P. xylostella, a notorious pest with worldwide distribution and a high capacity to adapt and develop resistance to insecticides.

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